K Force The Kristin Robotics Team Introductory Programming Tutorial 2014 For use with the teams squarebot training robots.

Transcription

1 K Force The Kristin Robotics Team Introductory Programming Tutorial 2014 For use with the teams squarebot training robots.

2 K Force Squarebot Programming Course Robot moves forward for two seconds #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop,) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop, reversed ) //botgear robot no controller move forwards for 2 seconds //designates start of the programme { //programme start bracket and white space It s good to start the programme with a comment briefly describing what it does wait1msec(3000); //allows time to switch the robot on and put it on the ground motor[leftwheel]=60; //sets the left motor to 60 motor[rightwheel]=60; wait1msec(2000); //sets the right motor to 60 - robot starts going forward //wait 2 seconds - robot moves forwards for 2 seconds motor[leftwheel]=0; //sets the left motor to 0 motor[rightwheel]=0; //sets the right motor to 0 - robots stops } //programme end bracket and white space Use white space, comments and indents. This makes it easier to fault find, amend and understand your programme. Important tips The programme could be written as below with no structuring, white space or comments and it would still work. As you can see it is much harder to read and very difficult to fault find. #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop,) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop,, reversed ) {motor[leftwheel]=60; motor[rightwheel]=60;wait1msec(2000);motor[leftwheel]=0;motor[rightwheel]=0;} You are advised to lay your programme out with structure, white space, comments for each line of code and a logical file name. /* A forward slash followed by an asterisk will isolate all the text after them in a paragraph so they are not read as code. Use these to make comments on your code and finish the paragraph with an asterisk and forward slash to complete the statement*/ // Two forward slashes will isolate the remaining text on one line only. No closing statement is required Save your programmes regularly!! Suggested file name structure: robot_programme_type_date_number Examples botgear_nc_fwd2secs_200214_2 (Botgear robot, no controller, forward for 2 seconds 20 Feb 2014, version 2) 2919a_kiwi chall_210514_8 (Team 2919A, Kiwi Challenge Competition, 21 st May 2014, version 8) marvin_3 sens_linetrk_ (Marvin, 3 sensor line tracking, 30 August 2012, version 12) When you have completed your programme compile and down load it using the F5 key. (Your programme must be correct!! All colons brackets and commands must be right. The compiler will give you suggestions for errors and corrections) Use the robot on and off switch to start your program or you can also use the start button in the Programme Debug window. Try using the stepping function which works through your programme step by step. This is very handy for fault finding.

3 Safety 1. Ensure all wires are properly tied up before operating a robot (Wires can get caught in gears and mechanisms which can cut them or cause short circuits resulting in expensive damage) 2. Ensure you and your team mates are clear before operating your robot (Fingers can get crushed in gears and mechanisms as well as eye hazards which can occur with moving parts such as lifts) 3. Do not operate your robot on a bench where it can possibly fall (If you are testing your robot on a bench ensure that someone is restraining it or it is on blocks. Robots can automatically go into autonomous routines on switch on. Falling onto the floor will almost certainly result in serious damage) Robot moves forward continuously #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop, reversed ) //botgear robot no controller continuous forward //designates start of the programme { //programme start bracket and white space wait1msec(3000); while(true) //allows time to switch the robot on and put it on the ground //While true, which is continuously, loop around between the brackets { //loop start motor[leftwheel]=60; //sets the left motor to 60 motor[rightwheel]=60; //sets the right motor to 60 } //loop end go back to the start of the loop } //designates end of the programme Loops are very powerful tools in programming. The while(true) loop will continue looping around indefinitely as there is nothing to make it false. As a result the programme is continually setting the motor speeds to the joystick settings with every loop. It does this thousands of times every second Do not let your robot bash into anything

4 Robot moves forward when switched #pragma config(sensor, in2, bumpswitch, sensortouch) #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop, reversed) //botgear no controller forward and stop controlled by a bumper switch connected to A/D port 1 //designates start of the programme { //designates start of programme int state=0; //creates and stores an integer called state which equals zero //this is used to determine whether the motors are to be switched on or off //when state=1 the robot will be running, when state=0 the robot will be stopped int value=0; //creates and stores an integer called value which equals zero //this is used to record an activation of the bumper switch //when switch contact is made (switch being held down)value will equal one int oldvalue=0; //creates and stores an integer called oldvalue which equals zero //this variable is used to determine if the switch operation is changing the state while(true) //while true (continuous loop) { //start of while bracket - programme continuously loops to here value=(sensorvalue(bumpswitch)); //sets 'value' to 1 if bump switch is pressed if(value==1 && oldvalue==0) //bumpswitch is depressed and old value equals zero { //start of if statement //switch was not pressed during the previous loop state = (1-state); wait1msec(300); //change state to 1 or 0 so motors switch on or off (state changes) //this is to 'debounce' the switch (ask your teacher about this) } //end of if statement oldvalue = value; //this will stop the state changing if the bumpswitch is pushed and held down if((state)==1) //if state equals 1 { //start of if statement

5 motor[leftwheel]=60; //sets the left motor to 60 motor[rightwheel]=60; //sets the right motor to 60 - robot starts going forward } //end of if statement else { //start of else statement motor[leftwheel]=0; //sets the left motor to 0 motor[rightwheel]=0; //sets the right motor to 0 - robots stops } //end of else statement } //end of while loop - programme repeats } //end of programme This programme uses variables which we set at the beginning. Variables are very powerful tools in programming. We can use them to name things and remember things. If we were controlling the robot with a simple on and off switch we could control the robot using a simple loop but because we are using a pushbutton switch we need to know whether the previous activation of the switch was to turn the robot on or off. We can use variables for this. Do not let your robot bash into anything. Turn it off and on using the switch..

6 Robot moves forward controlled by a switch and potentiometer #pragma config(sensor, in1, pot, sensorpotentiometer) #pragma config(sensor, in2, bumpswitch, sensortouch) #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop, reversed) //botgear no controller forward and stop controlled by a bumper switch connected to A/D port 2 //potentiometer connected to A/D port 1 controls robot speed and forward and reverse { //designates start of programme int state=0; //creates and stores an integer called state which equals zero //this is used to determine whether the motors are to be switched on or off //when state=1 the robot will be running, when state=0 the robot will be stopped int value=0; //creates and stores an integer called value which equals zero //this is used to record an activation of the bumper switch //when switch contact is made (switch being held down)value will equal one int oldvalue=0; //creates and stores an integer called oldvalue which equals zero //this variable is used to determine if the switch operation is changing the state while(true) //while true { //start of while bracket - programme continuously loops back to this point value=(sensorvalue(bumpswitch)); //sets 'value' to 1 if bump switch is pressed if(value==1 && oldvalue==0) //bumpswitch is depressed { //start of if statement //switch was not pressed during the previous loop state = (1-state); wait1msec(300); //change state to 1 or 0 so motors switch on or off (state must change) //this is to 'debounce' the switch (ask your teacher about this) } //end of if statement oldvalue = value; //this will stop the state changing if the bumpswitch is pushed and held down if((state)==1) //if state equals 1

7 { //start of if statement if(sensorvalue(pot)<512) //if the potentiometer (1-1024) is less than half way (512) { //start of if statement motor[leftwheel]=-128+((sensorvalue(pot))/4); //left motor set to increasing -ve setting motor[rightwheel]=-128+((sensorvalue(pot))/4);//right motor set to increasing -ve setting } //end of if statement else { //start of else statement motor[leftwheel]=-128+((sensorvalue(pot))/4); //left motor set to increasing +ve setting motor[rightwheel]=-128+((sensorvalue(pot))/4);//right motor set to increasing +ve setting } //end of else statement } //end of if statement else { //start of else statement motor[leftwheel]=0; //sets the left motor to 0 motor[rightwheel]=0; //sets the right motor to 0 - robots stops } //end of else statement } //end of while loop - programme repeats } //end of programme} This programme uses a potentiometer connected to Analogue/Digital input 2. This program also shows us how we can use basic maths in our programming to use an analogue sensor whose value is from and convert it to an analogue value from which we can use to control the motors forward and in reverse. Connect a potentiometer to A/D port 1 and put your robot on blocks so the wheels can spin freely.. A potentiometer has a limited range of rotation less than 360 degrees. It is used most commonly to measure angles. Do not connect a potentiometer on to a motor shaft or shaft that rotates more than 270 degrees otherwise you could destroy it.

8 Robot turns to the right #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop, reversed) //botgear robot no controller move forwards and turns right in increasingly sharper turns //designates start of the programme { //programme start bracket and white space wait1msec(3000); //wait for 3 seconds after switch on for programme to start motor[leftwheel]=60; //sets the left motor to 60 motor[rightwheel]=60; wait1msec(2000); //sets the right motor to 60 - robot starts going forward //wait 2 seconds - robot moves forwards for 2 seconds motor[leftwheel]=80; //sets the left motor to 80 motor[rightwheel]=40; wait1msec(2000); //sets the right motor to 40 - robots turns gently to the right //wait 2 seconds - robot gently turns to the right for 2 second motor[leftwheel]=80; //sets the left motor to 80 motor[rightwheel]=00; wait1msec(2000); //sets the right motor to 00 - robot turns on its right wheel for 2 seconds //wait 2 seconds - robot turns on its right wheel for 2 seconds motor[leftwheel]=80; //sets the left motor to 80 motor[rightwheel]=-80; wait1msec(2000); //sets the right motor to robots spins on axis to the right //wait 2 seconds - robot spins to the right on its axis for 2 seconds } //programme end bracket This programme shows how we can control the robots direction using the power to the two motors. The robot turns gently of on its axis using reverse power settings. Do not let your robot bash into anything as it turns in increasingly tight turns.

9 Robot controlled by a controller #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop, reversed) //botgear robot tank drive contol //designates start of the programme { //programme start bracket while(true) //programme continually loops back to while statement { //start of loop bifiautonomousmode = false; motor[leftwheel]=vexrt(ch3); motor[rightwheel]=vexrt(ch2); //no autonomous mode //set the left motor to the left joystick vertical channel //set the right motor to the right joystick vertical channel } //end of loop } //end of programme You can assign any channel or button on the controller to any motor or servo. The channel allocations can be found in the inventors guide or on line. Do not let your robot bash into anything as you drive it around.

10 Robot controlled by a controller with autonomous routine #pragma config(sensor, in2, bumpswitch, sensortouch) #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop, reversed) //botgear competition control simulation { //programme start bracket bifiautonomousmode = false; int auton=0; //no automatic autonomous mode //creates and stores an integer called auton which equals zero //records whether the autonomous bumpswitch has been pressed //when pressed the robot excecutes 20 seconds of autonomous code int drivercont=0; //creates and stores an integer called drivercont which equals zero //used to start the 1 minute 40 second driver control period //the robot will stop at the end of this period while(auton<1) //while autonomous button is not pressed { //start of while statement ClearTimer(T1); //timer T1 is set to zero auton=(sensorvalue(bumpswitch));//autonomous bumpswitch is checked } //end of while statement while(time100[t1]<200) //while timer is less than 20 seconds(time100=time in 100msec intervals) { //start of while statement - place your autonomous code in here motor[leftwheel]=60;//sets the left motor to 60 motor[rightwheel]=20;//sets the right motor to 20 - robot turns to the right for 20 seconds } //end of while statement while(drivercont==0) //while right button (Ch 6) on controller is not pressed { //start of while loop motor[leftwheel]=0; //sets the left motor to 0 motor[rightwheel]=0; //sets the right motor to 0 - robot stopped

11 ClearTimer(T2); drivercont=vexrt(ch6); //timer T2 is set to zero //driver control switch is checked (right switch) } //end of while loop //either right switches will activate driver control while(time100[t2]<1000) //while the timer is less than 100 seconds (1 minute 40 seconds) //time100=time in 100msec intervals { //start of while bracket motor[leftwheel]=vexrt(ch3);//set the left motor to the left joystick vertical channel motor[rightwheel]=vexrt(ch2);//set the right motor to the right joystick vertical channel } //end of while statement while(true) //while true - programme will remain in this loop { //start of while statement motor[leftwheel]=0; //sets the left motor to 0 motor[rightwheel]=0; //sets the right motor to 0 - robot stops - end of driver control } //end of while statement } //end of programme Use this programme template to simulate competition control in a match. You can place your autonomous code in the highlighted area and it will run for 20 seconds when you press the push switch. When either right button on the controller is pressed the robot will operate for 1 minute and 40 seconds simulating driver control after which it will stop. The robot will need to be turned off and back on to play further games.

12 Using quadrature shaft encoders

13 Using servomotors #pragma config(motor, port8, servo, tmotorservostandard, openloop) { while (true) { motor[servo] = 127; wait1msec(2000); motor[servo] = 0; wait1msec(2000); motor[servo] = -127; wait1msec(2000); //sets the servo to full deflection right //wait 2 second //sets the servo to centre //wait 2 second //sets the servo to full deflection left //wait 2 second } Servo motors only rotate through a fixed angle. They are good for controlling things and are not used for heavy loads. Servos use a value from -127 through to +127 to position the servo either side of centre.

14 Botgear Challenge Programme #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop, reversed) #pragma config(motor, port8, servo, tmotorservostandard, openloop) //botgear challenge programme { bifiautonomousmode = false; while(true) //programme start bracket //no autonomous mode //programme continually loops back to while statement { //start of loop motor[leftwheel]=vexrt(ch3); motor[rightwheel]=vexrt(ch2); //set the left motor to the left joystick vertical channel //set the right motor to the right joystick vertical channel motor[servo]=-(vexrt(ch3)-vexrt(ch2))/2; //set servo to difference between motors } //end of loop } //end of programme

15 Tile Trial Programme Template #pragma config(sensor, in2, bumpswitch, sensortouch) #pragma config(motor, port1, leftwheel, tmotorvex393highspeed, openloop) #pragma config(motor, port2, rightwheel, tmotorvex393highspeed, openloop, reversed) #pragma config(motor, port8, servo, tmotorservostandard, openloop) //botgear competition control simulation { //programme start bracket bifiautonomousmode = false; int auton=0; //no automatic autonomous mode //creates and stores an integer called auton which equals zero //records whether the autonomous bumpswitch has been pressed //when pressed the robot excecutes 20 seconds of autonomous code int drivercont=0; //creates and stores an integer called drivercont which equals zero //used to start the 1 minute 40 second driver control period //the robot will stop at the end of this period while(auton<1) //while autonomous button is not pressed { //start of while statement ClearTimer(T1); //timer T1 is set to zero auton=(sensorvalue(bumpswitch));//autonomous bumpswitch is checked } //end of while statement while(time100[t1]<200) //while timer is less than 20 seconds(time100=time in 100msec intervals) { //start of while statement - place your autonomous code in here motor[leftwheel]=60;//sets the left motor to 60 motor[rightwheel]=20;//sets the right motor to 20 - robot turns to the right for 20 seconds } //end of while statement while(drivercont==0) //while right button (Ch 6) on controller is not pressed { //start of while loop motor[leftwheel]=0; //sets the left motor to 0

16 motor[rightwheel]=0; ClearTimer(T2); drivercont=vexrt(ch6); //sets the right motor to 0 - robot stopped //timer T2 is set to zero //driver control switch is checked (right switch) } //end of while loop //either right switches will activate driver control while(time100[t2]<1000) //while the timer is less than 100 seconds (1 minute 40 seconds) //time100=time in 100msec intervals { //start of while bracket motor[leftwheel]=vexrt(ch3);//set the left motor to the left joystick vertical channel motor[rightwheel]=vexrt(ch2);//set the right motor to the right joystick vertical channel motor[servo]=-(vexrt(ch3)-vexrt(ch2))/2; //set servo to difference between motors } //end of while statement while(true) //while true - programme will remain in this loop { //start of while statement motor[leftwheel]=0; //sets the left motor to 0 motor[rightwheel]=0; //sets the right motor to 0 - robot stops - end of driver control } //end of while statement } //end of programme Use this programme template to simulate competition control in a match. You can place your autonomous code in the highlighted area and it will run for 20 seconds when you press the push switch. When either right button on the controller is pressed the robot will operate for 1 minute and 40 seconds simulating driver control after which it will stop. The robot will need to be turned off and back on to play further games.